remotelogbuffer.java

来自「主要是对串口驱动的的一些控制源码！！！ 在下载javacomm20-win32」· Java 代码 · 共 118 行

/**
 * $Log: RemoteLogBuffer.java,v $
 * Revision 1.2  2003/02/01 17:39:15  willaxt
 * now externalizable
 *
 * Revision 1.1  2003/01/16 13:12:40  mwulff
 * initial version
 *
 * Revision 1.4  2002/12/20 18:52:25  mwulff
 * no message
 *
 * Revision 1.3  2002/12/15 16:55:07  mwulff
 * adjusted to reorganisation of the client logging system
 *
 * Revision 1.2  2002/12/13 20:08:34  mwulff
 * no message
 *
 * Revision 1.1  2002/12/05 21:31:46  mwulff
 * initial version
 *
 */
package de.fhm.jkf.comm.cl;

import java.io.Serializable;
import java.util.Vector;

import org.apache.log4j.spi.LoggingEvent;

/**
 * @author	marten wulff
 * 
 * * <br><br><center><table border="1" width="80%"><hr>
 * <strong><a href="http://jkf.sourceforge.net">The JKF Project</a></strong>
 * <p>
 * Copyright (C) 2002 by Marten Wulff
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the <a href="http://www.gnu.org/copyleft/lesser.html">
 * GNU Lesser General Public License</a> along with this library; if not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA  02111-1307  USA
 * <hr></table></center>
 * 
 * This class is not externalizable, because it would need a public default
 * constructor. This would really break the singleton.
 * 
 * @stereotype singleton
 */
public class RemoteLogBuffer implements Serializable {
	
	private static RemoteLogBuffer instance = null;
	private static Object semaphore = new Object();

	private Vector logBuffer = null;
	
	/**
	 * Constructor for RemoteLogBuffer.
	 */
	private RemoteLogBuffer() {
		super();
		
		logBuffer = new Vector();
	}
	
	public static RemoteLogBuffer instance() {
		if(instance == null) {
			synchronized(semaphore) {
				if(instance == null) {
					instance = new RemoteLogBuffer();
				}
			}
		}
		
		return instance;
	}

	/**
	 * This method is called by class JKFAppender if
	 * a new LoggingEvent has arrived. The LoggingEvent
	 * is stored into a Vector for later transferation
	 * to the server.
	 * 
	 * @param ev a LoggingEvent that has to be stored
	 */
	public void addLogMessage(LoggingEvent ev) {
		logBuffer.addElement(ev);
	}
	
	/**
	 * Returns a clone of the logBuffer Vector, that holds
	 * all current LoggingEvents. After cloning the logBuffer
	 * is cleared.
	 * 
	 * @return Vector a clone of the logBuffer containing all
	 * 			current logs.
	 */
	synchronized Vector getLogMessages() {
		// clone the logBuffer
		Vector result = (Vector) logBuffer.clone();

		// clear the logBuffer
		logBuffer.clear();

		// return the clone
		return result;
	}

}